BRYMEN BM789 vs. BENNING MM 12 (APPA 506B) comparison - interested?

[joeqsmith]

It seems you do not know the difference between the shunts and the PTCs.  Odd as I had circled the parts with a line pointing to the damage.   I've also explained I don't collect any metrics on the current inputs.   

As for the voltage input, it's hard to say how well it would hold up.  Normally I just test them and collect the data and will leave the opinions to the experts.  I have ran other meters that used what appears to be a similar clamping technique with series PTSs.  The wouldn't suggest your meter would behave the same.  The only way to know it to run it to failure and see where it stacks up.         

I made some close ups in this post here:

https://www.eevblog.com/forum/testgear/brymen-bm789-vs-benning-mm-12-(appa-506b)-comparison-interested/msg3581849/#msg3581849

On the PTCs as well as the Shunt and some close ups in the input protection overall

Even if I had the meter in front of my, I lack the skill to be able to look at a product and determine how well it will perform.   I'm a bit jealous as most reviewers do seem to posses this skill where I have to design and construct transient generators and actually test them to know how they will perform.  A typically expert reviewer can provide an answer to how robust a meter is in seconds.  It takes me about a day. 

One of the more interesting handheld meters I looked at was the UNI-T UT181A.  It appears they used some decent parts in that meter.  They appeared to use a fairly common clamp design.  Still as a result of a poor layout the one I bought was damaged prematurely.   

[Cymaphore]

Even if I had the meter in front of my, I lack the skill to be able to look at a product and determine how well it will perform.   I'm a bit jealous as most reviewers do seem to posses this skill where I have to design and construct transient generators and actually test them to know how they will perform.  A typically expert reviewer can provide an answer to how robust a meter is in seconds.  It takes me about a day. 

One of the more interesting handheld meters I looked at was the UNI-T UT181A.  It appears they used some decent parts in that meter.  They appeared to use a fairly common clamp design.  Still as a result of a poor layout the one I bought was damaged prematurely.

I fully agree.

Probably I should be more careful about judging it only on a theoretic basis (components present and percieved to be of the correct size, percieved as being connected correctly and gaps are fine, brand). But my judgement was also based on long time usage experience. Not significant regarding it's extreme limits, you're right about that. Also the device survived the moron using it so far pretty well, for what it's worth.

I was just interested in an assessment based on what's visible out of interest and to maybe get a better understanding.

[joeqsmith]

If I owned a $2.00 meter and it sat in a box without batteries for 20 years, would you be impressed if I told you that my cheap meter lasted 20 years? 

If that same meter was only ever used to test 1.5V batteries and it never blew the front end, then I said it was in constant use for 20 years and was never damaged, would you be impressed?

There is a member here who reviews meters who commented after I damaged a Keysight  by rotating the switch a few thousand cycles.   I showed how the switch was made with a glass filled plastic and broke all the springs.   He explained how they rotate their switches 10's of thousands of cycles each year with no failure and made some half hour rebuttal video to tell us that.  Not one test was ran, and they couldn't even pull the meter apart to show if their spring was made from the same materials.  All they had was their expert opinion.       
 
I attempt to test them to some sort of common standards and then document my findings. My motives in running these tests are out of my own interest.   There's no  Patreon account and no begging for people to like and subscribe.   I've been called a fan boy from time to time, most of what I will comment on is based on the data I've collected.   

[Cymaphore]

Just for fun and out of interest I made a video to compare the bargraph and display reading speed (recorded in 60p) while "measuring" "music":

System Of A Down - Highway Song from the Album "Steal This Album" visualized on three Multimeters:

  * BENNING MM 12 (a.k.a. APPA 506B, in 40.000 count mode)
  * BRYMEN BM789
  * RS PRO S2 (a.k.a. APPA S2)
 
All devices are set to AC mV range, volume set to match the 400mV range of the MM12. Bad video quality and flickering on LCD displays due to my smartphone cameras poor performance in 60p and the ambient light. But it probably gives a good impression on the performance of the numeric readings and bar graphs of these meters.

Audio was inserted afterwards and synchronized manually.

Playback done on a DELL PRECISION M2800, output via headphone jack to the multimeters using standard lab cables, not coax.

Video was recorded on a MOTO G9 POWER.

[Cymaphore]

In my video about the SIEMENS B1023 I did two measurements using the BM789. In case someone is not interested in my whole blabla and love about the vintage meter, I put here two direct links to the timecode of the two tests involving the BM789 (first the SIEMENS, then the BRYMEN).

At 14:04: Measurement of a Photoresistor, to demonstrate how fast autoranging in resistance range is by waving my hand over the sensor

At 20:17: Measurement of an automatic colorchanging RGB-LED to demonstrate the performance in diode mode